What is magnesium chloride（hexahydrate & anhydrous magnesium chloride）？

Magnesium chloride (MgCl₂) is an inorganic salt mainly composed of magnesium ions (Mg²⁺) and chloride ions (Cl⁻), belonging to the chloride salt category. Due to different production processes in factories, it is also referred to as magnesium salt, brine flakes and other names.

I. Physical Properties of Magnesium Chloride

1. Appearance: Magnesium chloride falls into anhydrous magnesium chloride and magnesium chloride hexahydrate. Raw anhydrous magnesium chloride is mostly grey and turns white powdery after factory processing, similar to flour in form. Magnesium chloride hexahydrate comes in orange, transparent white, semi-transparent white, brown, milky white and crystalline forms.

2. Strong hygroscopicity: It has a bitter and salty taste, absorbs moisture easily to get damp and agglomerate when exposed to air, and will dissolve into liquid after long-term moisture absorption.

3. Solubility: Highly soluble in water; anhydrous magnesium chloride releases massive heat upon dissolution, and its aqueous solution is weakly acidic.

II. Classification of Magnesium Chloride

Magnesium chloride is divided into two main types: anhydrous magnesium chloride and magnesium chloride hexahydrate.

2.1 Anhydrous Magnesium Chloride

Content specifications: 97%, 98%, 99%, 99.5%, 99.9%

Forms: powdered anhydrous magnesium chloride, flakes, small and large lumps

Colors: Our Yuze anhydrous magnesium chloride produced by the magnesium chloride factory mainly includes off-white, raw color and pure white.

Grades: Industrial grade and food grade are our flagship products; reagent grade and pharmaceutical grade are also available.

2.2 Magnesium Chloride Hexahydrate

Classified by Purity & Application Industry

· Food Grade Magnesium Chloride Hexahydrate: Compliant with national standards for food additives with strictly controlled lead, arsenic and heavy metal content; mainly used as coagulant for brine-tofu making, bean product processing and beverage production.

· Feed Grade Magnesium Chloride Hexahydrate: Meets feed additive standards with fewer impurities than industrial grade, used for magnesium supplementation in feed for cattle, sheep, poultry, fish, shrimp and crabs.

· Industrial Grade Magnesium Chloride Hexahydrate: Used as additive or raw material in construction boards, chemical products, wastewater treatment, de-icing agent, petroleum, machinery, fireproof boards, coal mining, construction, printing and dyeing and other industries.

Classified by Physical Form

· Flaky Magnesium Chloride Hexahydrate: Traditionally crystallized from bittern in salt fields; our magnesium chloride factory mainly adopts acid synthesis (chemical synthesis) at present. Cost-effective and regularly stocked in our warehouse.

· Granular Magnesium Chloride Hexahydrate: Spherical/granular with good flowability, preferred for food and feed formulation.

· Powdered Magnesium Chloride Hexahydrate: Fine powder with quick dissolution for fine chemical industry and foliar fertilizer.

· Blocky Magnesium Chloride Hexahydrate: Large crystalline chunks for low-end industrial applications.

Classified by Production Process & Raw Material Source

1. Natural bittern crystallization type: Concentrated and crystallized from sea salt brine and salt lake brine (dominant product on the market).

2. Synthetic Magnesium Chloride Hexahydrate: Synthesized via reaction between magnesium oxide/magnesite and hydrochloric acid with controllable purity.

3. By-product type: Derived as by-products from potassium nitrate and pharmaceutical intermediate production; low price yet high impurity content and prone to caking.

4. Natural mineral type: Such as lake salt and well salt, major producing area: Qinghai, China.

Classified by Content: 43%, 44%, 45%, 46%, 47%

Classified by Product Quality

· Premium Grade (EU Standard): Our Yuze product certified by EU standards, clear aqueous solution like pure water, low impurities, actual content up to 47.2% against marked 46%, resistant to caking and storable for over 2 years under proper sealing.

· First Grade: Commonly used grade with stable content (actual ~46.8% vs marked 46%), slight anti-caking property, mostly clear solution with tiny impurities and flocs.

· Standard Grade: Cost-effective for industries with loose quality requirements, e.g. coal mining for sulfur removal, fire prevention and dust retention of coal.

Our Yuze magnesium chloride factory, specializing in anhydrous magnesium chloride and magnesium chloride hexahydrate with 13 years of industry experience, supplies diversified specifications with competitive pricing, stable content and punctual delivery; we can recommend optimal anhydrous magnesium chloride or magnesium chloride hexahydrate per customers’ practical usage.

III. Packaging of Anhydrous Magnesium Chloride and Magnesium Chloride Hexahydrate

Mainstream Market Packaging

Inner polyethylene plastic bag + outer plastic woven bag.

Standard sizes: 25kg/bag, 50kg/bag, 500kg/bag, bulk jumbo bag.

Customized packaging available for supermarket sales with minimum order quantity required due to packaging mould opening for manufacturers.

This is the prevailing packaging for food-grade and industrial-grade magnesium chloride; inner bag for moisture-proof and outer bag for physical protection against deliquescence. Bags shall be tightly sealed with product name, batch number, content, net weight and manufacturer marked on outer surface.

IV. Storage Requirements for Anhydrous Magnesium Chloride and Magnesium Chloride Hexahydrate

Specific Storage Rules

· Replace damaged inner bags immediately once breakage occurs.

· Seal or heat-seal bag openings tightly; never leave bags open.

· Keep goods off ground with pallets or storage racks underneath.

· Dry, ventilated and clean warehouse required.

· Ambient relative humidity controlled below 60%.

· Store away from water sources, rainwater and water pipelines.

· Moisture-proof ground treatment with no standing water allowed.

Core storage principle for magnesium chloride summarized in six Chinese characters: Dry, Seal, Isolate. Properly stored products can be preserved for 1–2 years; inferior-grade products may lump within several days without proper management.